1,021 research outputs found
The Effects of Cultural Factors on Safety in Aviation Focusing on Asian and Western Cultures
Several aviation accidents from the past, such as the Asiana Flight 214 crash at San Francisco International Airport in 2015, have highlighted possible effects of Korean hierarchy culture on the safety of flight. Previous research conducted primarily with the use of surveys revealed that Asian pilots are less likely to report an unsafe condition out of fear that it will damage their relationships with coworkers and superiors. Western pilots see reporting as dealing with the problem and not a person, thus they feel more open to it. This study looked at student pilots’ ability to recognize and deny an unsafe flight instruction from a superior based on their cultural background. Ten Western and ten Korean participants were asked to fly around a mountainous region with low-laying clouds in a flight simulator. During the flight, participants were given instructions by the researcher, who pretended to be a flight instructor. One of the instructions was made intentionally unsafe and non-compliant with the Federal Aviation Administration regulations; participant reactions to the instructions were recorded. Significantly more Korean than Western participants were able to recognize the unsafe instruction, but significantly more Western pilots denied the unsafe instruction. It is recommended for the aviation industry to recognize and consider cultural differences when developing regulations and training programs, such as Crew Resource Management, to reassure the Safety Culture in aviation. Further research is suggested to determine other cultural factors that can affect safety of flight
Bloody nipple discharge in an infant
Although milky nipple discharge appears frequently in infants, bloody nipple discharge is a very rare finding. We experienced a 4-month-old, breast-fed infant who showed bilateral bloody nipple discharge with no signs of infection, engorgement, or hypertrophy. The infant's hormonal examination and coagulation tests were normal, and an ultrasound examination revealed mammary duct ectasia. The symptoms resolved spontaneously within 6 weeks without any specific treatment, except that we advised the mother to refrain from taking herbal medicine. Since no such case has been previously reported in Korea, we present this case with a brief review of the literature
Cell-free synthesis of functional phospholipase A1 from Serratia sp.
Additional file 1: Figure S1 Gas chromatography analysis of sesame oil incubated with cell-free synthesized PLA1
Clinical Characteristics of Rhabdomyolysis in Children : Single Center Experience
Purpose Rhabdomyolysis is a metabolic disorder in which the content of damaged muscle cells is released into plasma. Its manifestations include asymptomatic, myalgia, gross hematuria, and complications of acute kidney injury. Because of limited data on rhabdomyolysis in children, we performed this study to determine clinical characteristics of rhabdomyolysis in children. Methods We retrospectively reviewed the records of patients with rhabdomyolysis who were treated at the Pusan National University Children’s hospital from January 2011 to July 2016. The diagnostic criteria were serum myoglobin level of ≥80 ng/mL, exclusive of acute myocardial injury, cardiac arrest, and brain damage. Results Forty-five patients were enrolled; mean age, 116±68 months. Of these, 35 were boys and 10 were girls. Twenty-six patients experienced myalgia and 12 patients showed gross hematuria. Among these, seven patients initially had both myalgia and gross hematuria. The most common causes of rhabdomyolysis were infection, physical exertion, prolonged seizures, metabolic abnormalities, and drug addiction. Acute kidney injury (AKI) was the most common complication, followed by disseminated intravascular coagulation. Thirty-seven patients improved with sufficient fluid supply but two patients underwent hemodialysis due to deterioration of kidney function. Gross hematuria, positive occult blood test, and positive urine protein were more common in patients with AKI than in those without AKI. Conclusions In children, infection was the most common cause of rhabdomyolysis. Most patients recovered by sufficient fluid therapy. However, in severe cases, especially in patients with underlying kidney disease, hemodialysis may be necessary in the present study
A Rare Case of Unilateral Pleural Effusion in a Pediatric Patient on Chronic Peritoneal Dialysis: Is it a Pleuroperitoneal Leakage?
Non-infectious complications of peritoneal dialysis (PD) are relatively less common than infectious complications but are a potentially serious problem in patients on chronic PD. Here, we present a case of a non-infectious complication of PD in a 13-year- old boy on chronic PD who presented with symptoms such as hypertension, edema, dyspnea, and decreased ultrafiltration. Chest and abdominal radiography showed pleural effusion and migration of the PD catheter tip. Laparoscopic PD catheter reposition was performed because PD catheter malfunction was suspected. However, pleural effusion relapsed whenever the dialysate volume increased. To identify peritoneal leakage, computed tomography (CT) peritoneography was performed, and a defect of the peritoneum in the left lower abdomen with contrast leakage to the left rectus and abdominis muscles was observed. He was treated conservatively by transiently decreasing the volume of night intermittent PD and gradually increasing the volume. At the 2-year follow-up visit, the patient had not experienced similar symptoms. Patients on PD who present with refractory or recurrent pleural effusion that does not respond to therapy should be assessed for the presence of infection, catheter malfunction, and pleuroperitoneal communication. Thoracentesis and CT peritoneography are useful for evaluating pleural effusion, and timely examination is important for identifying the defect or fistula
APE1 Promotes Pancreatic Cancer Proliferation through GFRα1/Src/ERK Axis-Cascade Signaling in Response to GDNF
Pancreatic cancer is the worst exocrine gastrointestinal cancer leading to the highest mortality. Recent studies reported that aberrant expression of apurinic/apyrimidinic endodeoxyribonuclease 1 (APE1) is involved in uncontrolled cell growth. However, the molecular mechanism of APE1 biological role remains unrevealed in pancreatic cancer progression. Here, we demonstrate that APE1 accelerates pancreatic cancer cell proliferation through glial cell line-derived neurotrophic factor (GDNF)/glial factor receptor α1 (GFRα1)/Src/ERK axis-cascade signaling. The proliferation of endogenous APE1 expressed-MIA PaCa-2, a human pancreatic carcinoma cell line, was increased by treatment with GDNF, a ligand of GFRα1. Either of downregulated APE1 or GFRα1 expression using small interference RNA (siRNA) inhibited GDNF-induced cancer cell proliferation. The MEK-1 inhibitor PD98059 decreased GDNF-induced MIA PaCa-2 cell proliferation. Src inactivation by either its siRNA or Src inhibitor decreased ERK-phosphorylation in response to GDNF in MIA PaCa-2 cells. Overexpression of GFRα1 in APE1-deficient MIA PaCa-2 cells activated the phosphorylation of Src and ERK. The expression of both APE1 and GFRα1 was gradually increased as progressing pancreatic cancer grades. Our results highlight a critical role for APE1 in GDNF-induced pancreatic cancer cell proliferation through APE1/GFRα1/Src/ERK axis-cascade signaling and provide evidence for future potential therapeutic drug targets for the treatment of pancreatic cancer
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A systemic review and meta-analysis on the antihypertensive effect of aromatherapy essential oils
Purpose: This study is a systemic review of experimental results on the effects of aromatherapy on blood pressure.
Materials and Methods: Journal articles published to December, 2017, were retrieved from twelve databases. Randomized controlled trials in which were evaluated for changes in blood pressure following aromatherapy were selected. Risks of bias were assessed using the risk-of-bias (ROB) tool of the Cochrane Collaboration. Meta-analysis were dine using RevMan.
Results: Of the 2545 articles retrieved from the electronic databases, 580 duplicate articles and 1891 articles that were unrelated to the PICO (patient/problem, intervention, comparison, outcome) elements or did not satisfy the inclusion criteria excluded. Of the remaining 74 articles, 15 found to satisfy the inclusion criteria after full-text review and therefore selected for analysis. The findings of meta-analysis of 11 of these 15 articles revealed that essential oil inhalation and massage effectively decreased both systolic (n = 379; mean difference [MD], -4.72; 95% confidence interval [CI], -8.38 to -1.07) and diastolic (n = 379; MD, -2.42; 95% CI, -4.46 to -0.38) pressure.
Conclusions: Essential oil inhalation and massage therapy can effectively decrease systolic and diastolic pressure in health adults as well as in patients with hypertension
Nature-derived epigallocatechin gallate/duck’s feet collagen/hydroxyapatite composite sponges for enhanced bone tissue regeneration
Scaffolds mimicking structural and chemical characteristics of the native bone tissues are critical for bone tissue engineering. Herein, we have developed and characterized epigallocatechin gallate/duck's feet collagen/hydroxyapatite (EGCG/DC/HAp) composite sponges that enhanced the bone tissue regeneration. The three-dimensional composite sponges were synthesized by loading various amounts (i.e. 1, 5 and 10 μM) of EGCG to duck feet derived collagen followed by freeze-drying and then coating with hydroxyapatite. Several measuremental techniques were employed to examine the properties of the as-fabricated composite sponges including morphology and structure, porosity, compressive strength, etc. and as well compared with pristine duck feet derived collagen. SEM observations of EGCG/DC/HAp sponges showed the formation of a highly porous collagen matrix with EGCG embodiment. The porosity and pore size of sponges were found to increase by high EGCG content. The compressive strength was calculated as 3.54 ± 0.04, 3.63 ± 0.03, 3.89 ± 0.05, 4.047 ± 0.05 MPa for 1, 5 and 10 μM EGCG/DC/HAp sponges, respectively. Osteoblast-like cell (BMSCs isolated from rabbit) culture and in vivo experiments with EGCG/DC/HAp sponges implanted in nude mouse followed by histological staining showed enhanced cell internalization and attachment, cell proliferation, alkaline phosphatase expressions, indicating that EGCG/DC/HAp sponges have ahigh biocompatibility. Moreover, highEGCG content in the EGCG/DC/HAp sponges have led to increased cellular behavior. Collectively, the 5 μM of EGCG/DC/HAp sponges were suggested as the potential candidates for bone tissue regeneration.This research was supported by Technology Commercialization Support Program [grant number
814005-03-3-HD020], MIFAFF; and Basic Science Research Program [grant number NRF2017R1A2B3010270]
through the National Research Foundation of Korea, Ministry of Science, ICT and Future Planning, Republic of Korea.info:eu-repo/semantics/publishedVersio
Unitary relation between a harmonic oscillator of time-dependent frequency and a simple harmonic oscillator with and without an inverse-square potential
The unitary operator which transforms a harmonic oscillator system of
time-dependent frequency into that of a simple harmonic oscillator of different
time-scale is found, with and without an inverse-square potential. It is shown
that for both cases, this operator can be used in finding complete sets of wave
functions of a generalized harmonic oscillator system from the well-known sets
of the simple harmonic oscillator. Exact invariants of the time-dependent
systems can also be obtained from the constant Hamiltonians of unit mass and
frequency by making use of this unitary transformation. The geometric phases
for the wave functions of a generalized harmonic oscillator with an
inverse-square potential are given.Comment: Phys. Rev. A (Brief Report), in pres
Computed tomography–assessed presarcopenia and clinical outcomes after laparoscopic surgery for rectal cancer
Purpose Previous studies have reported that presarcopenia negatively affects rectal cancer treatment. However, most studies have analyzed patients including majority of open surgery, and the association between presarcopenia and clinical outcomes after laparoscopic rectal cancer surgery remains unclear. This study aimed to evaluate the impact of presarcopenia on the clinical and oncological outcomes after laparoscopic rectal cancer surgery. Methods Three hundred and one patients undergoing laparoscopic rectal cancer surgery between December 2009 and May 2016 were enrolled. Body composition was assessed using computed tomography by measuring the muscle and fat areas at the third lumbar (L3) vertebra. The L3 skeletal muscle area was used to calculate the skeletal muscle index and evaluate presarcopenia. Results Presarcopenia was more common in older (≥70 years, P=0.008) or female patients (P=0.045). Patients with presarcopenia had decreased skeletal muscle area (P<0.001), lower hemoglobin level (P=0.034), longer time to first flatus (P<0.001), and more frequent surgical site infection (P=0.001). However, survival rates were not significantly different between those with and without presarcopenia. Conclusion Computed tomography-assessed presarcopenia was associated with delayed functional recovery and increased surgical site infection, although it was not revealed as a prognostic factor for oncological outcomes
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